1. Field of the Invention
The present invention relates to a positioning jig and a method of adjusting a position, which are applicable to a tray (conveying tool) for conveying a semiconductor wafer when mounting the semiconductor wafer to be heated thereon and carrying the semiconductor wafer to a reflow furnace.
2. Description of Related Art
A special-purpose conveying tool has been used during semiconductor manufacturing steps such as a heat treatment step and a conveying line in the past and has conveyed many semiconductor wafers (hereinafter, simply referred to as “wafer” in case of need). The sizes of wafers to be conveyed have been often different from each other in different semiconductor manufacturing steps. Accordingly, each time the size of wafer varies, the conveying tool has been changed.
In order to exclude such a change step of the conveying tool, a conveying tool which can convey wafers having a plurality of sizes has been known (see Japanese Patent Application Publication No. H06-151550 and Japanese Utility Model Application Publication No. S62-026037). Japanese Patent Application Publication No. H06-151550 has disclosed a wafer fork. In such a wafer fork, holding pins are set in setting holes of a wafer fork body due to diameters of the wafers to be conveyed. This enables the wafers having a plurality of sizes to be conveyed.
Japanese Utility Model Application Publication No. S62-026037 has disclosed a wafer-holding table. By such a wafer-holding table, a conveying beam which moves upward or downward and horizontally by means of a vertical cylinder and a horizontal cylinder conveys wafers.
On the wafer-holding table, pins supporting the wafer have at least three species of heights. A group of the pins having the same height is arranged around the same circumference. The groups of the pins which have different heights are arranged around the same circumferences in order of height outward so that the group of pins having the height corresponding to each of the sizes of the wafer can support the wafer having the corresponding size. The wafer is positioned by allowing it to contact the group of pins having a height with next higher level to that of the group of pins supporting the wafer.
FIG. 1 shows another conveying tool 300 of related art for a semiconductor wafer, which is applicable to a case of conveying the wafers having a plurality of sizes. In the conveying tool 300 for the semiconductor wafer shown in FIG. 1, a base plate 31 and conveying guides 32 are fastened by bolts 34 and the like.
The base plate has an opening 35, which has a diameter that is smaller than a diameter of the wafer W1, at its middle. Three pins 36A, 36B, and 36C for supporting the wafer W1 are arranged around the same circumference on the base plate 31 and three guides 37A, 37B and 37C for preventing misalignment of the wafer W1 are arranged around the same circumference.
Further, three pins 38A, 38B and 38C for supporting the wafer W2 having a diameter that is larger than the diameter of the wafer W1 are arranged around the same circumference on the base plate 31 and three guides 39A, 39B and 39C for preventing misalignment of the wafer W2 are arranged around the same circumference.